No abstract

Tocopherols are natural antioxidants found in all vegetable oils. They are important dietary nutrients and thus breeding for increased tocopherol content is a new and important objective in canola (Brassica napus L.). Tocopherols exist in four forms (α‐, β‐, γ‐, and δ‐tocopherol) differing in molecular structure and biological effectiveness. In the seed oil of canola, mainly α‐ and γ‐tocopherol are found with an α/γ‐tocopherol ratio of about 0.5. Three canola populations of doubled haploid lines were grown in three to four field environments to analyze genetic variance and genotype × environment interactions as well as heritability of tocopherols and correlations with other seed components. Significant genotypic differences occur, but large genotype × environment interactions are the major source of variation. Heritability of tocopherol was low in all three populations; the estimates ranged from 0.23 to 0.44 for α‐tocopherol and from 0.33 to 0.50 for γ‐tocopherol. Heritability for tocopherol content is considerably lower than heritability of oil content (0.56–0.90), protein content (0.43–0.76), or glucosinolate content (0.91–0.95). No correlation between α‐ and γ‐tocopherol or between tocopherol and oil, protein, and glucosinolate content was detected. Individual tocopherols can be increased independently of each other and without affecting other major quality traits.

Armoracia rusticana (horseradish), a\ud member of the Brassicaceae family, has been known\ud since ancient times as a folk medicinal herb and as a\ud plant of nutritional value and culinary interest. Currently horseradish is cultivated for its thick, fleshy and\ud white roots which have a delicious intense pungency\ud and for its tender leaves which are frequently used for\ud salad mixed to other vegetables. The traditions to use\ud horseradish plant for medicinal purpose are still\ud applied in many countries. Horseradish is a rich source of a number of bioactive compounds such as\ud glucosinolates (GLSs) and their breakdown products.\ud Sinigrin is the dominant glucosinolate in both leaves\ud and roots. Recent studies have shown that crude plant\ud extracts have a complex profile of naturally occurring\ud GLSs, with particular regard to sprouts. The increasing\ud interest in these secondary metabolites, associated to\ud the long and diffuse tradition of using horseradish in \ud food preservation and as condiment in many parts of \ud the world, is generating new applications of this plant \ud in several agro-industrial and pharmaceutical sectors \ud and is encouraging the use of its roots and leaves in \ud functional food and medicine for human health. A \ud bibliography review is discussed on ethnobotanical \ud aspects and uses of this plant, as well as knowledge \ud about its flavour compounds and GLS content and \ud composition. This study summarizes also the updated \ud information concerning the influence of the genotype \ud and environment on GLS profile in horseradish

Resveratrol is a phytoalexin produced in various plants like wine, peanut or pine in response to fungal infection or UV irradiation, but it is absent in members of the Brassicaceae. Moreover, resveratrol and its glucoside (piceid) are considered to have beneficial effects on human health, known to reduce heart disease, arteriosclerosis and cancer mortality. Therefore, the introduction of the gene encoding stilbene synthase for resveratrol production in rapeseed is a tempting approach to improve the quality of rapeseed products. The stilbene synthase gene isolated from grapevine (Vitis vinifera L.) was cloned under control of the seed-specific napin promotor and introduced into rapeseed (Brassica napus L.) by Agrobacterium-mediated co-transformation together with a ds-RNA-interference construct deduced from the sequence of the key enzyme for sinapate ester biosynthesis, UDP-glucose:sinapate glucosyltransferase (BnSGT1), assuming that the suppression of the sinapate ester biosynthesis may increase the resveratrol production in seeds through the increased availability of the precursor 4-coumarate. Resveratrol glucoside (piceid) was produced at levels up to 361 microg/g in the seeds of the primary transformants. This value exceeded by far piceid amounts reported from B. napus expressing VST1 in the wild type sinapine background. There was no significant difference in other important agronomic traits, like oil, protein, fatty acid and glucosinolate content in comparison to the control plants. In the third seed generation, up to 616 microg/g piceid was found in the seeds of a homozygous T3-plant with a single transgene copy integrated. The sinapate ester content in this homozygous T3-plant was reduced from 7.43 to 2.40 mg/g. These results demonstrate how the creation of a novel metabolic sink could divert the synthesis towards the production of piceid rather than sinapate ester, thereby increasing the value of oilseed products.

A reduction in acid detergent lignin content in oilseed rape resulted in an increase in seed oil and protein content. Worldwide increasing demand for vegetable oil and protein requires continuous breeding efforts to enhance the yield of oil and protein crop species. The oil-extracted meal of oilseed rape is currently mainly used for feeding livestock, but efforts are undertaken to use the oilseed rape protein in food production. One limiting factor is the high lignin content of black-seeded oilseed rape that negatively affects digestibility and sensory quality of food products compared to soybean. Breeding attempts to develop yellow seeded oilseed rape with reduced lignin content have not yet resulted in competitive cultivars. The objective of this work was to investigate the inheritance of seed quality in a DH population derived from the cross of the high oil lines SGDH14 and cv. Express. The DH population of 139 lines was tested in field experiments in 14 environments in north-west Europe. Seeds harvested from open pollinated plants were used for extensive seed quality analysis. A molecular marker map based on the Illumina Infinium 60 K Brassica SNP chip was used to map QTL. Amongst others, one major QTL for acid detergent lignin content, explaining 81% of the phenotypic variance, was identified on chromosome C05. Lines with reduced lignin content nevertheless did not show a yellowish appearance, but showed a reduced seed hull content. The position of the QTL co-located with QTL for oil and protein content of the defatted meal with opposite additive effects, suggesting that the reduction in lignin content resulted in an increase in oil and protein content.